In general, there are known toys for shooting a target with a light beam gun. In these toys, whether a target is hit or not is determined by detecting the light beams from the light beam gun by a sensor disposed to the target.
However, since the sensor has directivity, when the light beams enter obliquely the detection surface of the sensor, the light beams are often not detected. That is, when the target is shot outside of the detection angle of the sensor, even if the target is hit with the light beams, the light beams are not detected.
As a technology for solving the above problem, there is a detection device disclosed in, for example, Japanese Patent Application Publication No. 7-111319. The detection device comprises a light receiving device and a sensor (a detection device). The light receiving device has a light receiving surface such that light beams (shooting spot) are diffused on the light receiving surface and the light beams are transmitted through the light receiving surface, and the sensor detects the light beams received by the light receiving device. Further, the light receiving surface is formed in an outwardly convex shape. In the detection device, since the light beams entering the light receiving surface reach the sensor after they are diffused on the light receiving surface and transmitted therethrough in every direction, shooting executed outside of the detection angle of the sensor can be detected.
In the detection device described above, however, since the light beams are diffused and transmitted, an amount of light that reaches the detection surface of the sensor is reduced. Accordingly, there is a possibility that detection sensitivity is deteriorated.